Trailer coupling



Aug. 20, 1935. R. E. LEPPO 2,012,103

TRAILER COUPLING Filed Oct. 20, 1950 5 Sheets-Sheet 1 IN VEN TOR.

/-v Fal/Dh 5`Leppo A TTORNEYS 5f Sheets-Sheet 2 I N VEN TOR.

Fai/oh E. L epjoo BYMQ e ATTORNEY` ug." 20, 1935. R. E. I EPPO I'TRAILER COPLING Filed oct. 2o, 195o 3 Sheets-Sheet 3 Patented Aung.'20, 1935 c? UNiTEDfsTAr i aoialoaf I v 'rRAILERjooUPLING' Ralph E.'Leppo', Inkster, Mich.; assigimr" 0f one'- hall:` to Stephen A.GI'iggaDet'roit, Mich.

Application October 20, 1930, Serial'No; 489,806

7. Claims. (Cl. .2W-5373.1) n

My inventionrelatestoimprovements in trail-v ersv and particularlyV toimproved mechanismy whereby a two wheel semi-trailer ymay becoupled toatractor vehicle. y An objectoi 'my invention is to simplify theoperation of coupling a semi-trailer vehicleto its tractor and,v at the'same time,'to provide aicoupling which permits universal movementbetween secure connection underall conditions.

yMore specifically it is an object of my invenf tion to provide'a .balland socket coupling between tractor and trailer wherein the'socketincludes am'ovable member-which is adapted to 'shift from its normalposition upon engagement with the ball to'permit entrance of the ballwithin the socket and 'subsequently automatically returnA to its normalposition, in-which position the bally is'retained rmly in the socket'. t

= yAfurther object of my invention isto provide, in conjunctionwithsucha universal c zoupling,y

v means whereby the semi-trailer is supported at four points, just asi's'the' ordinary four 'wheel- Vehicle. That'is tosay,"'means'arefassociated with my improved universal couplingwherebythe front end of the semi-trailer, which is supported-by the rear-of thetractor' vehicle, restsy upon a supporting surface at each side thereofrather" than simply upon the coupling which is located centrally of thetwo sides. #j V 1 Another object of my invention is to so design 'thisfour point suspension that it is available in all relative positions oftrailer and tractor.`v` In my improvedstructure it isimmaterial Whetheror not the tractor vehicle extends at right anglesto the trailen' oreven doubled back at an acute angle therewith. This greatly facilitatesmaneu-l vering and unloading of the trailer.l

A further very important object of my inven-r tion is to eliminate asubstantial number of the elements customarilyr utilized in a f tractortrailer coupling mechanism and'simplify the tractor for the purpose ofvreducing the manufacturing costs'- In securing this improved resultI`conternplate 'arranging a fixed element upon a tractor andanotherfixed element upon a'trailergwhich elements are adapted to provide alarge vbearing area for vsupporting the front en-d of the` trailer uponthe` tractor as indicated in the paragraph above, and which also permitswinging movement Vin a horizontal planeas well as rockingv movement in.ag vertical plane. I These' movements' are'essential to successfultractor trailer couplings. Hitherto' tractor trailer couplings havecustomarily included, a vfifth wheel bearing-member adapted? to supthetwo coupled elements While maintaining a v the balil and port the frontend lof the trailenwhich fthwheel was'pivoted in a suitable'manner, asupon a horizontal pin, for swinging movement in a vertical plane. e Thecoupling between the front end ofthe trailer and the fth wheel of thetractor'wasV of a -`construction to permit swivelling movement betweenthe vtractor andtrailer for-turning pure' poses, etc. e

My improved couplingeliminates the necessity.l for :theusual fifth wheelcoupling. exclusive` 'ofthe socket 'member within ywhich a ball maybelocked. Two perfectly rigidmembers, of simple design and low cost,cooperate with one another to permit universal movemen'tbetween` thetractor and trailer. f j

Still another object of my invention is to prov vide easily 'manipulablelocking mechanism for positively retaining'thebaIl Within the socket in.addition to the'meanswhereby it is normally re-` tained insuchrposition, the said locking mechanismbeing adapted to positivelyactuatethe movable member of the socket to permitfreljease of` the balltherefrom upon disengagement of the trailer from thetractor. Means areprovided whereby this movablef socket member may be locked inleither itsopenfor closed position, butj asf it is only necessary 4to manipulate`the member for the purpose of releasing the ball from within thesocket.' As .heretofore stated, theball'itself shiitsthe member uponengagement therewith during the rcoupling"operati-on` l v- Qtherobjectsand meritorious features of myV invention reside in the simplicityvof'arr'angement and minimum of parts which Ihave'utilized to.accomplish the above`objects, and will be'appar-- ent from the followingdescription taken in conjunction with thedrawings wherein:

' Fig. `1 illustrates the two units coupled.

Fig. 2 is atop plan view of the front end of the trailer, gsh0wing thesocket element,

@boat 'to be Fig. 3fis atop plan View of the rearend'of lthe tractor,showingthe bam,r v i A Fig; 4 isa section'on line 4 4 of Fig. 3, f Fig.5'is a centralglongitudinal section` through socket assemblyV in theirgcoupled position, f l" "Fig, 6 is a section ofl Ef-Bof Fig. 2*, Fig. "7is a detail ofthe movablesocket element; and

Fig. 8 is'an elevation thereof. j Trailers of the semi-trailer; or fifthwheel, type v are customarily provided vwith some means atthefrontthereof and'on each side yfor supporting the structurewhen'itisinctV coupled to a tractor,

soV

After this operation the two ends of the ve-` hicles are coupled to oneanother in various ways to permit the tractor to draw the trailer. y 1In my improved structure I provide lthe rear end I0 of the tractor witha raised platform I2 which is composed of a flanged plate member I4.This hanged plate member is secured to the frame of the tractor in anydesired manner, as by means of the rivets It. The extreme rear end ofthe raised platform I2 slopes downwardly as at I8 across its entirewidth to provide a sloping guideway.

Secured longitudinally to the under face of member I 4 are Z-shapedbrackets 20 and 22. These brackets are so spaced as to form a guidechamber extending centrally of the member I4 throughout a portion of itslength. Securely positioned at spaced apart positions within this guidechamber are blocks 24 and 2G, thebolts 28 and 3B being utilized toposition the element. A third block 32 is free to slide within vtheguide chamber and the ball 34 is secured thereto by means of the nut 36.The shank 38 of ball 34 extends through an elongated slot 4I! in the topof flanged plate I4. Blocks 24 and 26 are provided with projecting studs42 and 44 respectively, while each end of block 32 is provided withsimilar studs 45 and 48. These studs constitute seats for oppositeextremities of coil springs 50 and 52 and in this way the ball 34 isfree to slide to a limited extent longitudinally in either directionwithin the slot 40.

A trough-like member 54 which constitutes an arcuate bearing surface issecured to the underside of the front of the trailer vehicle frame 55and extends across a portion of the width thereof. "A fixed portion. 58of the ball socket is secured to the upper rear face lof member 54 bymeans such as the bolts S0, the forward face 62 of said socket member 58being adapted to seat the ball 34 snuglyabout a portion of the sphericalsurface thereof. A pair of arms `64 and 66 are secured, as by spotwelding, along the under portion of frame 55, as clearly indicated inFig. 2. 'Ihe forward portion of member 54 is provided with asubstantially V-shaped cut away portion 55, vtlieyside marginal portions67 and 68 of and 56 by means of the bearing arms 'I5 and 18.

The web shaped portion 'I2 has `a central flange 'i9 which is provided`lwith aneyeletvSIll at its extremity. -A ,coil spring 82 connects theweb member 'I2 with the front frame channel 84 as clearly indicatedinFgs. 2 and 5.

Bearing arm 'I6 is provided with a square aperture into which the squareextremity 86 of shaft 88 is adapted to seat.y The other extremity ofshaft 88 is journalledin a dependingbracke et 90 which is secured to anouter trailer frame channel 92, as by the rivets 94. A handle is keyedto the shaft, this handle constituting the means for positivelyactuating the movable socket member 1D. Toward its outer extremityhandle` 96 is provided with an aperture 98 adapted to aline withapertures in the depending arms |00 and |52 o-f a U-shaped bracket IMwhich is secured tc the lower ilange of channel 92, as by the bolt |06.

The full line position of the handle indicated in Fig. l represents theposition thereof when the movable socket member 'l0 is in a position topositively retain the ball Within the socket or,

in other words, in lockedposition. A pin IBS, secured to the trailerframe in any desired manner may be inserted through the alined holes inarms IDD and I D2 and hole 98 of the handle 95 to secure them in theirfull line position. Should it'prove desirable to lock the handle in itsdotted liney position, in which position the movable socket member 10 isadapted to permit unobstructed removalof they ball 34 from the socket,the aperture IID may be` locked by means of a pin as hereto-foredescribed inregard to the full line position.

Operation of the coupling mechanism will be apparent from the foregoingdescription. As the tractor vehicle is backed under the trailer thelowermost portion of the trough like member 54 slides up the guide kI8into-the position indicated in Fig. 7. In this position the bottom y ofthe member 54 has a bearing upon the top.

of the raised platform I2 substantially throughout its entire width. Asthe tractor is further backed the ball 34 will be guided by meansof theanges 65 and 58 to a position indicated in Fig.v 5 by the dotted ball atthe extreme right thereof. At this point it will bear against the webportion I2 of movable socket element I0 and begin to rotate the latterabout its bearing arms 'I6 and I8 as an axis. An intermediate positionlis illustrated by the second, or left, dotted ball,

at which point themovablesocket element l!!l has reached theperpendicular position indicatedA in dotted lines in Fig. 5, itsdirection of movement beingv indicated by the arrow H2. Still furtherrearward movement of the tractor and ball vwill bring the latter to restagainst the face 52 of the fixed socket element 58 and the movablesocket member 'I0 will have reached the limit -of its movement in thatdirection. Thisl movement is limited by the stop'face I I6 of fixedsocket member 58, in which the hub I I8 of the movable socket 'Ill isadapted tor rest. Having reached this point the spring 82 will draw themovable socket elementV 'I0 back into its initial position whereby theball is firmly locked within the socket so provided. The tractor andtrailer are now coupled and it will be seen that the ball and socketpermit swivelling movement between the tractor and trailer, the troughlike member 54 having a substantial bearing surface on the plate memberI4 at all times to provide a four` point suspension, so to speak, forthe front end of the trailer. 'Ihrough the arcuatesupporting surface ofthe trough like member 54 a rocking movement between it and the platewithout any substantial frictional resistance whatsoever is renderedpossible. In other Words, twdintegral rigid members, plate I4 and thetrough like member `54, provide a universal coupling of a simplicitylhitherto unknown and efficient in operation.

To provide further security againstpossible unaclaro?,

ksaid.vehicle:and extending transverselyy of. the, lengthofsaid-bearinga second component socket coupling, the movable.' socketmember` 1D lmay bef locked in position by means o-f the` pin '|08hitherto described. This not. essentialgh'owber including its ballsocket are carried by the' ever, inasmuchas thecoupling so provided-.issubstantially proof against uncoupl'ing without therprecauton ofproviding apositive lock. Thus it is apparentV that the l'coupling takesplace automatically and the only ktime when it is necessary to. ractuatethe movable socket element 'lll is. when release of the ball `from-thesocket is desired- .-At ythat timev the element la is actuated bymeansof the handle; S6 to permit withdrawal of .the tractorL and ballfrom the trailer socket.' y f v The yielding seat for ball 34provided-'by springs'f andi52" absorbs jarring which wouldvvv normallybe transmitted to the trailer and its 4load upon retardation andacceleration of the tractor, and also absorbs thev shock of coupling..The most delicate goods may be carried bythe trailer with the assurancethat there will be no jar during coupling or hauling of the trailerwhich would endanger its load.

In the drawings the supporting plate I4 and `its associated ball 3d areillustrated in conjunction withthe tractor while the trough like mem--trailer. It will be understood that these elemen'ts may be reversed andthe coupling will function equally satisfactorily. Inasmuch as themajority of tractor trailer coupling mechanisms now in use carry theball upon the front end of the rtrailer and a socket arrangement uponthe tractor, I contemplate reversing'the parts as illustrated so that aninverted trough like structure 54 will be positioned upon the rear endofthe tractor operable to receive the ball on the front end of thetrailer. It will furthermore be understood that my inventioncontemplates not only the use of' a continuous arcuate surface extendingklaterally across a substantial portion of the width of either thetractor or the trailer,v but also the use of spaced apart arcuaterocking members located on each side of the ball socket, and suchstructure would function equally well and the arrangement is simply amatter of choice. The important feature resides in the provisionofspaced'apart arcuate supporting surfaces adapted to rcooperate y acomposite socket secured to the concave face of said bearingintermediate its ends, a pair of spaced apart arms secured to theunderside of said vehicle and extending transversely ofthe length ofsaid bearing, and a second vcomponent socket element pivotally mountedbetween' said arms in operative relation to said rst mentioned compositeelement.

2. .In combinationk with a vehicle adapted to be coupled to anothervehicle, a laterally extending arcuate bearing surface secured to theunderside 'of said vehicle, vone of two component portions of acomposite socket secured to the concave face of said bearingintermediate its ends,` a pair of spaced apart arms secured 'to theunderside` of element pivotally mountedbetween said arms inforward'centrai part of said arcuate surface, said cut away portionbeing bent lunder lalong opposed edges thereof to form a guide way forthe element to be positioned within said socket.

3. Infcombin'ation 4with a vehicle adapted to be'coupledtoanotherfvehicle, a' laterally ex-l underside of said vehicle, one oftwo component portionsv of a composite socket secured to the concavefaceof fsaid bearing intermediate its ends, Aa pair of spaced apartfarmssecuredto the underside of said vehicle and extending transversely ofthelength of said bearing, a second component socket element pivotallymounted be? tween said arms'in operative relation to rsaid nrst 1operative relation tosaid rst'znenticned composite element, and acutaway portion in the ll@y ' tending arcuate ybearing surface securedto the mentioned composite element, anda shaft jour- `nalleol on oneside of the vehicle frame for rotation therein having oneextremityfixedly secured n to the pivotal point of said pivoted componentsocketelernent whereby the latter may be manually` actuated. f

4. In combination with a vehicle adapted to be coupled to anothervehicle,y a laterally extending arcuate bearing surface secured to theunderl. o side of saidvehicle, one of two component porv.tions of acomposite socket secured to the concave face of saidv bearingintermediate its ends, a. pair of spaced lapart arms secured to theunderside of said vehicle and extending transversely of the length ofsaid'b-earing, a second component socket element pivotally mountedbetween said arms in operative relation to said first mentionedAcomposite element, a shaft `journalled on one side of the vehicle framefor rotation therein having one Lextremity fixedly secured tothe pivotalpoint of said pivoted component socket element'whereby the latter may bemanually actuated, and means associated with said shaft adjacent thejournalled` portion thereof and co-operable with said vehicle frame forlocking the shaft against rotation.

5. Mechanism for supportably'coupling twojve v hicles togethercomprising, in combination, a flat bearing surface on one of saidvehicles, a rounded bearing surface on the other of said vehicles ex..

l tending a substantial portion of the width thereof and adapted to makeline contact with said flat bearing surface to support onejvehicle inover# lapping relation on the'other, a slot vin the forward portion ofthe rounded bearing surface havingV converging side .walls terminatingin a socket rearwardly thereof g amember yieldably mounted astrideV theslot and having a segmental portion fiat bearing surface adapted to beguided through the slot into the socket when vthe bearing `surfaces arebrought into contact supporting relationship,

forming a component part of the socket, and a ball element extendingfromthe surfacev of the said member being yieoldable to permit entrancevof. said ball element through the slot and into the socket butpreventing withdrawal of said ball element thereby coupling saidvehicles together. 6. Mechanism forsupportably coupling two Vvehiclestogether including, in combination, a hole low arcuate bearing structureon one of said vehicles having a bearing apex extending laterallyacrossthevehicle for a substantial portion of its width, a slot in theforward portion of said arcuate structure having converging side wallsterminating-ina socket positioned at the bearing apex of said arcuatestructure, a member pivotally mounted insaid structure on an axisextend. ing radially with respect to said socket and parallel to thebearing apex of said arcuate structure,-

said member having a segmental portion forming a component part of saidsocket and having a flange portion adapted to lie astride the slot,`said hicles in overlapping relationship comprising, in

combination, a flat bearing surface on one of said vehicles having aball element protruding therefrom, a rounded bearing surface on theother of said vehicles adapted to make bearingfcontact atvthe apex ofsaid rounded surface, a slot in said rounded surface on one side of theapex thereof having converging Walls terminating in a socket positionedat the bearing apex of said rounded surface, a segmental portion of saidsocket pivotally mounted on -either side of said socket and providedwith a ange yieldably re` strainedto liel across said slot, saidsegmental p0rtion adapted upon engagement of said ball with said angetomove on its pivot in an arcuate path about said socket to permit theball to seat therein and further adapted upon seating of the ball Withinthel socket to return to its normal restrained position looking the ballWithin the socket.

